funcs/func_logic.c

   1 /*
   2  * Asterisk -- An open source telephony toolkit.
   3  *
   4  * Copyright (C) 1999 - 2006, Digium, Inc.
   5  * Portions Copyright (C) 2005, Anthony Minessale II
   6  *
   7  * See http://www.asterisk.org for more information about
   8  * the Asterisk project. Please do not directly contact
   9  * any of the maintainers of this project for assistance;
  10  * the project provides a web site, mailing lists and IRC
  11  * channels for your use.
  12  *
  13  * This program is free software, distributed under the terms of
  14  * the GNU General Public License Version 2. See the LICENSE file
  15  * at the top of the source tree.
  16  */
  17
  18 /*! \file
  19  *
  20  * \brief Conditional logic dialplan functions
  21  *
  22  * \author Anthony Minessale II
  23  */
  24
  25 #include "asterisk.h"
  26
  27 ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
  28
  29 #include <stdio.h>
  30 #include <stdlib.h>
  31 #include <string.h>
  32 #include <sys/types.h>
  33
  34 #include "asterisk/module.h"
  35 #include "asterisk/channel.h"
  36 #include "asterisk/pbx.h"
  37 #include "asterisk/logger.h"
  38 #include "asterisk/utils.h"
  39 #include "asterisk/app.h"
  40
  41 static int isnull(struct ast_channel *chan, char *cmd, char *data,
  42                   char *buf, size_t len)
  43 {
  44         strcpy(buf, data && *data ? "0" : "1");
  45
  46         return 0;
  47 }
  48
  49 static int exists(struct ast_channel *chan, char *cmd, char *data, char *buf,
  50                   size_t len)
  51 {
  52         strcpy(buf, data && *data ? "1" : "0");
  53
  54         return 0;
  55 }
  56
  57 static int iftime(struct ast_channel *chan, char *cmd, char *data, char *buf,
  58                   size_t len)
  59 {
  60         struct ast_timing timing;
  61         char *expr;
  62         char *iftrue;
  63         char *iffalse;
  64
  65         data = ast_strip_quoted(data, "\"", "\"");
  66         expr = strsep(&data, "?");
  67         iftrue = strsep(&data, ":");
  68         iffalse = data;
  69
  70         if (ast_strlen_zero(expr) || !(iftrue || iffalse)) {
  71                 ast_log(LOG_WARNING,
  72                                 "Syntax IFTIME(<timespec>?[<true>][:<false>])\n");
  73                 return -1;
  74         }
  75
  76         if (!ast_build_timing(&timing, expr)) {
  77                 ast_log(LOG_WARNING, "Invalid Time Spec.\n");
  78                 return -1;
  79         }
  80
  81         if (iftrue)
  82                 iftrue = ast_strip_quoted(iftrue, "\"", "\"");
  83         if (iffalse)
  84                 iffalse = ast_strip_quoted(iffalse, "\"", "\"");
  85
  86         ast_copy_string(buf, ast_check_timing(&timing) ? iftrue : iffalse, len);
  87
  88         return 0;
  89 }
  90
  91 static int acf_if(struct ast_channel *chan, char *cmd, char *data, char *buf,
  92                   size_t len)
  93 {
  94         AST_DECLARE_APP_ARGS(args1,
  95                 AST_APP_ARG(expr);
  96                 AST_APP_ARG(remainder);
  97         );
  98         AST_DECLARE_APP_ARGS(args2,
  99                 AST_APP_ARG(iftrue);
 100                 AST_APP_ARG(iffalse);
 101         );
 102         args2.iftrue = args2.iffalse = NULL; /* you have to set these, because if there is nothing after the '?',
 103                                                                                         then args1.remainder will be NULL, not a pointer to a null string, and
 104                                                                                         then any garbage in args2.iffalse will not be cleared, and you'll crash.
 105                                                                                     -- and if you mod the ast_app_separate_args func instead, you'll really
 106                                                                                         mess things up badly, because the rest of everything depends on null args
 107                                                                                         for non-specified stuff. */
 108
 109         AST_NONSTANDARD_APP_ARGS(args1, data, '?');
 110         AST_NONSTANDARD_APP_ARGS(args2, args1.remainder, ':');
 111
 112         if (ast_strlen_zero(args1.expr) || !(args2.iftrue || args2.iffalse)) {
 113                 ast_log(LOG_WARNING, "Syntax IF(<expr>?[<true>][:<false>])  (expr must be non-null, and either <true> or <false> must be non-null)\n");
 114                 ast_log(LOG_WARNING, "      In this case, <expr>='%s', <true>='%s', and <false>='%s'\n", args1.expr, args2.iftrue, args2.iffalse);
 115                 return -1;
 116         }
 117
 118         args1.expr = ast_strip(args1.expr);
 119         if (args2.iftrue)
 120                 args2.iftrue = ast_strip(args2.iftrue);
 121         if (args2.iffalse)
 122                 args2.iffalse = ast_strip(args2.iffalse);
 123
 124         ast_copy_string(buf, pbx_checkcondition(args1.expr) ? (S_OR(args2.iftrue, "")) : (S_OR(args2.iffalse, "")), len);
 125
 126         return 0;
 127 }
 128
 129 static int set(struct ast_channel *chan, char *cmd, char *data, char *buf,
 130                size_t len)
 131 {
 132         char *varname;
 133         char *val;
 134
 135         varname = strsep(&data, "=");
 136         val = data;
 137
 138         if (ast_strlen_zero(varname) || !val) {
 139                 ast_log(LOG_WARNING, "Syntax SET(<varname>=[<value>])\n");
 140                 return -1;
 141         }
 142
 143         varname = ast_strip(varname);
 144         val = ast_strip(val);
 145         pbx_builtin_setvar_helper(chan, varname, val);
 146         ast_copy_string(buf, val, len);
 147
 148         return 0;
 149 }
 150
 151 static struct ast_custom_function isnull_function = {
 152         .name = "ISNULL",
 153         .synopsis = "NULL Test: Returns 1 if NULL or 0 otherwise",
 154         .syntax = "ISNULL(<data>)",
 155         .read = isnull,
 156 };
 157
 158 static struct ast_custom_function set_function = {
 159         .name = "SET",
 160         .synopsis = "SET assigns a value to a channel variable",
 161         .syntax = "SET(<varname>=[<value>])",
 162         .read = set,
 163 };
 164
 165 static struct ast_custom_function exists_function = {
 166         .name = "EXISTS",
 167         .synopsis = "Existence Test: Returns 1 if exists, 0 otherwise",
 168         .syntax = "EXISTS(<data>)",
 169         .read = exists,
 170 };
 171
 172 static struct ast_custom_function if_function = {
 173         .name = "IF",
 174         .synopsis =
 175                 "Conditional: Returns the data following '?' if true else the data following ':'",
 176         .syntax = "IF(<expr>?[<true>][:<false>])",
 177         .read = acf_if,
 178 };
 179
 180 static struct ast_custom_function if_time_function = {
 181         .name = "IFTIME",
 182         .synopsis =
 183                 "Temporal Conditional: Returns the data following '?' if true else the data following ':'",
 184         .syntax = "IFTIME(<timespec>?[<true>][:<false>])",
 185         .read = iftime,
 186 };
 187
 188 static int unload_module(void)
 189 {
 190         int res = 0;
 191
 192         res |= ast_custom_function_unregister(&isnull_function);
 193         res |= ast_custom_function_unregister(&set_function);
 194         res |= ast_custom_function_unregister(&exists_function);
 195         res |= ast_custom_function_unregister(&if_function);
 196         res |= ast_custom_function_unregister(&if_time_function);
 197
 198         return res;
 199 }
 200
 201 static int load_module(void)
 202 {
 203         int res = 0;
 204
 205         res |= ast_custom_function_register(&isnull_function);
 206         res |= ast_custom_function_register(&set_function);
 207         res |= ast_custom_function_register(&exists_function);
 208         res |= ast_custom_function_register(&if_function);
 209         res |= ast_custom_function_register(&if_time_function);
 210
 211         return res;
 212 }
 213
 214 AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Logical dialplan functions");